Marker buoy control



Nov. '14, 1967' J. A. BURKHARDT MARKER BUOY CONTROL Fi led Dec. 23, 1965 RUPTURE DISK BUOY RUPTURE DISK LE A o LIN E FlG. 2.

7 sum: LINES VALVE ACTUATOR SWIVEL 35 FILQ wu N-E INVENTOR.

JOSEPH A.B'URKHARDT,

BYja EM 6 TRANSM'ISSON um: T0 REMOTE PLATFORM .A-LEAD LINE 1 AT TQORN EY.

United States Patent 3,351,965 MARKER BUSY CONTROL Joseph A. Burkhardt, Houston, Tex., assignor to Esso Production Research Company Filed Dec. 23, 1965, Set. No. 515,810 4 Claims. (Cl. 98)

This invention relates to the location of underwater sites, and more particularly to apparatus for controlling a marker buoy adapted to rise to the surface of a watercovered area so that the site may be located by operating personnel in surface craft or aircraft.

For various reasons it is often desirable to determine the exact location of a water-submerged site.'For example, after an oil or gas Well has ben drilled, often it is desirable to re-enter the well for workover purposes or the like. Problems associated with finding the exact location of the Well can be quite severe, particularly when the well is being produced through flowlines extending from the well head to a remote drilling platform or to the shore. While navigational aids such as radar and loran can be used to find the approximate location of a Well head, considerable time must be expended in order to actually locate the well head.

In accordance with the teachings of the present invention, a marked buoy is used for the purpose of locating the exact site of an underwater location. When the underwater site is a well head, the buoy may be connected to the well head by guide lines such as are customarily used for the purpose of inserting well tools into the well head opening. Connected to the buoy is a first fluid conduit having a closure member therein adapted to normally prevent fluid flow therethrough. A second fluid conduit runs from the underwater site to a remote location such as a drilling platform. Connected between the first and second fluid conduits is a conduit controller means adapted to take in and let out the first fluid conduit so that the marker buoy can be drawn down into the water so as not to interfere with surface craft operations and the like, or can be allowed to surface simply by letting out the conduit. The controller means lets out the conduit responsive to application of a given fluid pressure on the interior of both of the fluid conduits sufiicient to open the closure means. The first fluid conduit is taken in so as to submerge the marker buoy by reclosing the closure member and applying to the conduit means a given fluid pressure less than the pressure required to open the closure means.

More specifically, the invention contemplates that the first conduit means shall be attached to a reel that is driven by the fluid motor. Valve control means connected to the motor permits fluid flow therethrough so as to rotate the motor and reel in one direction and to let out the first fluid conduit after the motor in the first fluid conduit is ruptured. The valve mechanism has a second actuated position whereby closure of the closure member and application of fluid pressure to the system will cause the fluid motor to rotate in the opposite direction to drive the reel so as to retract the first fluid conduit and the marker buoy to the normal operating positions thereof.

Objects and features of the invention not apparent from the above discussion will become evident upon consideration of the following detailed description thereof taken in connection with the accompanying drawings, wherein:

FIG. 1 is an illustration of an underwater well site making use of the invention;

FIG. 2 is a schematic diagram of the invention illustrating the details of the conduit controller; and

FIG. 3 is a cross-sectiona1 view of a portion of the 3,351,965 Fatented Nov. 14, 1957 marker buoy 8 of FIG. 1 illustrating the constructional details of a closure member suit-able for use in the invention.

With reference now to FIG. 1, there is illustrated a marker buoy 3 floating on the surface 7 of the water in the immediate vicinity of an underwater site, such as that of a Well head 4. The buoy is shown as being connected to the well head by guide lines 11 suitable for use in conducting pipe :and well tools into the well head in accordance with well-known techniques. The well head is shown as having a funnel-shaped opening 6 having a wireline plug 6A for sealing the opening. A fluid conduit or lead line 13 also is connected to the marker buoy and extends downwardly from the buoy to a buoy control unit 15 in the immediate vicinity of the well head 4. A transmission line 19 to a remote platform or other operating location is connected to the conduit 13 through the buoy control unit so as to provide liquid or fluid flow therethrough, as

. will be described below. The buoy control unit is affixed to an anchor 29 on the Water bottom by support members 27. A production flow line 5 extends from the well head 4 to the operating location. The well head is provided with the usual surface casing 2 and tubing 3 extending to the subsurface productive Zones. Included within the buoy control unit 15 is a reel 21 On which the conduit 13 is wound, and control apparatus 23 and 25, which Will be described in connection with FIG. 2. A pulley or sheave 17 is provided for facilitating the reeling in and letting out of the conduit 13 by the reel 21. A closure member 9, illustrated more perspicuously in FIG. 3, is provided for sealing the upper end of the conduit 13.

With reference now to FIG. 2, there is shown in greater detail the apparatus for controlling the letting out and taking in of the conduit 13. The reel 21 on which the conduit is wound is driven by a fluid-actuated motor 29 through a gear train comprising gear 31 attached to the output shaft of motor 29, and a gear 33 meshing with gear 31 and afiixed to the drive shaft of reel 21. The drive shaft 32 of the reel is supported by conventional journalling means, not shown.

The motor 29 rotates in one direction or the other, depending upon the direction of flow of fluid, preferably a liquid, therethrough. The fluid is derived from line 19, and the direction of flow is controlled by valves 51A,

51B, 51C, 53A, 53B, and 53C. In the normal position of buoy 8, that is, with the buoy retracted or submerged, valves 51A, 51B, and 51C are closed, and valves 53A, 53B, and 530 are open. As illustrated, valves 51C and 53C are connected to conduit 19. Valve 53A is connected between valve 51C and motor fluid connection 29A through lines 55 and 43. Likewise, valve 51A is connected between valve 53C and motor fluid connection 2913 through lines 57 and 41. Valves 51B and 5313, respectively, are connected to lines 43 and 41 by branch lines 47 and 49, respectively, and exhaust to the sea or to a suitable sump. Thus, when valves 51C, 53A, and 53B are simultaneously opened, fluid from line 19 will flow through the valves and through motor 29 to drive reel 21 in one direction. Likewise, when valves 53C, 51A, and 51B are simultaneously opened, fluid will flow through these valves and through motor 29 so as to drive reel 21 in the opposite direction. Valve 530 is opened by a gear train including pinion gear 61 on shaft 32 and gear 63 driving worm gear shaft 69, which in turn rotates gear 71 to o en or close valve 53C. Similarly, pinion 61 drives gear 65 to rotate shaft 67 and gear 73 to open or close valve 510. Valve 51C is closed when buoy 8 is in the most submerged position; i.e., when conduit 13 is wound on reel 21 to a desired extent. Valve 53C is closed when conduit 13 is wound oif reel 21 so that marker buoy 8 is at the surface of the water.

Valves 51A, 51B, 53A, and 53B are simultaneously actuated by valve-actuator 25 which rotates a shaft 79 for simultaneously opening and closing the valves. The valve-actuator comprises a housing 81 which acts as a piston chamber for a pair of opposed pistons 83 and 85 connected to opposite ends of a shaft 87. A rack 91 on the shaft 87 drives a pinion gear 89 so as to rotate the pinion gear 89 and drive shaft 79 responsive to longitudinal movement of the connecting rod 87. A differential pressure chamber 99 having chambers 1% and 1&1 therein connected by an orifice 192 is connected between conduit 19 and conduit 13 through lines 97 and 37 and through a swivel connection 35 on the drive shaft 32. Drive shaft 32 may be partially hollow so that one end of conduit 13 may be connected thereto. The chambers 100 and 101 are respectively connected to the piston chambers for pistons 83 and 85 through lines 93 and 95, respectively. The pistons 83 and 85 are of different areas so that when equal pressures are present in chambers 100 and 101, the pistons 83 and 85 will be in the position shown so that valves 51A and 51B will be closed, and valves 53A and 53B will be open. However, when fluid flows through the differential pressure chamber 99, the pressure in chamber 101 will be greater than that in chamber 100, causing the pistons 83, 85 and connecting rod 87 to move upwardly, as viewed, thus opening valves 51A and 51B and closing valves 53A and 533.

The construction of the closure member 9 at the buoy end of conduit 13 is illustrated in FIG. 3. A rupture disc 9D is housed in a threaded housing 913 which is connected to the buoy 8 and to the lead line 13. A cap 9A having a bore 9C therethrough holds the rupture disc 9D in place in the housing 9B.

The over-all operation of the apparatus described above is as follows. Let it be assumed that the buoy is submerged or retracted, with the various valves open or closed as described above, and with rupture disc in place so that no fluid can flow through conduit 13. Since valve 51C is closed, no fluid can flow through the motor through valves 53A and 53B. Likewise, since valve 51B is closed, no liquid can flow through the motor through valves 51A and 53C. The buoy, therefore, will remain in its retracted position. To allow the buoy to rise to the earths surface, it is necessary only to increase the pressure in line 19 so that disc 9D will rupture. Fluid will flow through line 97, through the differential pressure chamber 99, through line 37, and conduit 13. The differential pressure produced in chamber 99 will cause connecting rod 87 to move upwardly, as viewed, rotating pinion 89 and opening valves 51A and 51B, and closing valves 53A and 53B. Fluid from line 19 will flow through valves 53C and 51A, motor 29, and valve 51B, thus actuating the motor to drive reel 21 so as to unreel conduit 13 and permit the buoy 8 to rise to the water surface. Valves 51C and 53C Will be driven to close valve 53C when the buoy surfaces, and to open valve 51C immediately after motor 29 begins rotating. When well head operations have been completed, a new rupture disc 9D can be placed in the housing 9B and a lower pressure exerted on conduit 19. Since no liquid will flow through the chamber 99, the valve actuator 25 will return to its normal position, as shown, thus opening valves 53A and 53B, and closing valves 51A and 5113. Since valve 51C is now open, fluid will flow through motor 29 via the valves 53A and 538, thus winding the conduit 13 back on the reel 21 until valve 51C is again closed. Valve 53C will be again opened. The buoy 8 will again be retracted and the system will remain quiescent until the rupture disc is again ruptured. Thus,

surface vessels can pass directly over the well head location without disturbing well operations in any way.

While there has been shown and described what at present is considered the preferred embodiment of the invention, other modifications will be apparent to those skilled in the art which do not depart from the scope of the broadest aspects of the invention as defined by the appended claims.

\Vhat is claimed is:

1. Apparatus for controlling a water-submerged marker buoy for locating an underwater site, comprising:

a reel;

flexible first fluid conduit means at least partially windable on said reel, adapted for connection at one end thereof to said buoy;

a closure member for said conduit means at the buoy end thereof;

second fluid conduit means; and

control means connected between said first and second conduit means for unwinding said first conduit means from said reel, responsive to given fluid pressure exerted on the interior of said second conduit means to open said closure member and permit said buoy to rise to the surface, and responsive to reclosure of said closure member and to a lower fluid pressure in said second conduit means to rewind said first conduit means on said reel.

2. Apparatus in accordance with claim 1 wherein said control means comprises:

fluid motor means for driving said reel in one direction of rotation or the other, dependent on the direction of fluid flow through said motor; and fluid control means connected to said second conduit means for gating fluid flow through said motor means responsive to opening of said closure member, and to gate fluid flow through said motor means to drive said motor means in a direction to wind said first fluid conduit means on said reel responsive to closure of said closure member and pressurization of said second conduit means.

3. Apparatus in accordance with claim 2 wherein said fluid control means comprises:

first valve means connected to said motor means for providing a first unidirectional flow path for fluid flow in one direction through said mtoor means;

second valve means connected to said motor means for providing a second unidirectional path for fluid flow through said motor means in a direction opposite to said one direction;

third valve means drivingly connected to said motor means and fluidly coupling said second conduit means to said second valve means, adapted to be driven by said motor means from a normally closed position when said first conduit means is wound on said reel to an open position thereof;

fourth valve means drivingly connected to said motor means and fluidly coupling said second conduit means to said first valve means, adapted to be driven by said motor means from a normally open position when said first conduit means is Wound on said reel to a closed position thereof; and

valve actuator means connected to said first and second valve means and hydraulically connected between said first and second conduit means for closing said first valve means and opening said second valve means when said first conduit means is closed by said closure member, and for opening said first valve means and closing said second valve means when said first conduit means is opened to permit fluid flow therethrough.

4. Apparatus in accordance with claim 3 wherein said valve actuator means comprises:

a fluid restriction means coupling said first conduit means to said second conduit means such that fluid flow therethrough produces a differential pressure thereacross;

differential pressure actuator means hydraulically coupled to opposite sides of said restriction means References Cited FOREIGN PATENTS 481,129 8/1916 France.

5 MILTON BUCHLER, Primary Examiner.

T. MAJOR, Assistant Examiner. 

1. APPARATUS FOR CONTROLLING A WATER-SUBMERGED MARKER BUOY FOR LOCATING AN UNDERWATER SITE, COMPRISING: A REEL; FLEXIBLE FIRST FLUID CONDUIT MEANS AT LEAST PARTIALLY WINDABLE ON SAID REEL, ADAPTED FOR CONNECTION AT ONE END THEREOF TO SAID BUOY; A CLOSURE MEMBER FOR SAID CONDUIT MEANS AT THE BUOY END THEREOF; SECOND FLUID CONDUIT MEANS; AND CONTROL MEANS CONNECTED BETWEEN SAID FIRST AND SECOND CONDUIT MEANS FOR UNWINDING SAID FIRST CONDUIT MEANS FROM SAID REEL, RESPONSIVE TO GIVEN FLUID PRESSURE EXERTED ON THE INTERIOR OF SAID SECOND CONDUIT MEANS TO OPEN SAID CLOSURE MEMBER AND PERMIT SAID BUOY TO RISE TO THE SURFACE, AND RESPONSIVE TO RECLOSURE OF SAID CLOSURE MEMBER AND TO A LOWER FLUID PRESSURE IN SAID SECOND CONDUIT MEANS TO REWING SAID FIRST CONDUIT MEANS ON SAID REEL. 